1. Synthesis of Potassium Dioxalatocuprate Dihydrate
Lab 7

2. Outline Purpose Definitions Experiment Reaction Calculations
Precautions
Equipment Setup
What to turn in today
Spring Break and Next Lab Reminder

3. Purpose
This lab will help you gain an understanding of stoichiometric relationships between reactants and products of chemical reactions. This includes an understanding of concepts such as limiting reagents, yields, and percent error.

4. Important Points
Stoichiometry is the study of mass relationships in a chemical reaction.
The law of definite proportions states that compounds or elements react chemically to form a new compound in definite proportions.
Before any attempt at calculations are made, reactions have to be balanced first. Only then can we obey the law of definite proportions.
The limiting reagent is the reagent that runs out first in a chemical reaction.

5. Reaction
Add two water soluble compounds together to form an insoluble solid that precipitates out.
Filter out all excess water soluble reagent.
Isolate the precipitate on filter paper utilizing three rinses and vacuum filtration.
Determine the percent yield recovered.

6. Reaction Reagents Products A B C
1CuSO45H2O(aq)+2K2C2O4H2O(aq) K2[Cu(C2O4)2]2H2O(s)+
D E
5H2O + 1K2SO4(aq)
copper potassium oxalate potassium potassium
sulfate monohydrate dioxalatocuprate sulfate
pentahydrate dihydrate

7. Calculations Moles of A = Moles of B = Limiting Reagent (LR) Ratio =
Moles of CLR = (moles of LR) x
Theoretical Yield = (moles of C) x (fw of C)
% Yield = x 100%

8. Precautions
Filtrate should be disposed of in the wet copper waste container only.
Dry product and waste copper sulfate should be disposed of in the dry copper waste container only.
After all product is scraped off, filter paper should be placed on the paper towel next to the dry / wet waste containers.
Cleaning and maintaining balances…

9. Equipment
Hotplate function
Ice bath preparation
Filtration setup

10. Equipment Setup

11. Equipment Setup
Filtering flask

12. Safety Concerns Reagents: Eye Contact: Skin Contact: Inhalation:
Acetone
Cupric Sulfate
Denatured Alcohol
Potassium Oxalate
Eye Contact:
Stinging, tearing, redness, pain, irritation, tissue burns, conjunctivitis, ulceration, clouding of cornea, and blurred vision
Skin Contact:
Defatting, dehydration, irritation, redness, pain, drying, flaking, cracking, itching, and severe burns
Inhalation:
Irritation, ulceration, and perforation of the respiratory tract, coughing, sore throat, shortness of breath, dizziness, dullness, drowsiness, loss of appetite, inability to concentrate, headache, nervousness, cramps, CNS depression, narcosis, and unconsciousness. Fumes from heating may cause symptoms similar to a cold.
Ingestion:
Abdominal pain, nausea, vomiting, headaches, gastritis, gastrointestitis, intoxication, blindness, and death. Aspiration into the lungs can cause severe lung damage.

13. Next Week: Spring Break
No labs next week

14. In 2 Weeks: Lab 8 Reminder
Read the required reading material from your textbook and lab manual.
Complete your pre-lab questions.
Study for the quiz.
Submit your Lab 7 Report.